A Cosmologist’s Guide to the End of the Universe | Katie Mack and Debbie Millman | TED

Katie. Katie. >> Yes. >> Yes. >> Yes. >> Hi. >> Hi. >> Hi. >> Hi. >> Hi. >> Hi. >> I understand that you earned your >> I understand that you earned your >> I understand that you earned your private pilot license during the private pilot license during the private pilot license during the pandemic pandemic pandemic >> Yes. >> Yes. >> Yes. >> and are now doing aerobatic training. >> and are now doing aerobatic training. >> and are now doing aerobatic training. I've heard of acrobatic training, but I've heard of acrobatic training, but I've heard of acrobatic training, but never aerobatic training. never aerobatic training. never aerobatic training. >> Mhm. >> Mhm. >> Mhm. >> Tell us what that is. >> Tell us what that is. >> Tell us what that is. >> Yeah, so aerobatics is flying the >> Yeah, so aerobatics is flying the >> Yeah, so aerobatics is flying the airplane in unusual ways. So, things airplane in unusual ways. So, things airplane in unusual ways. So, things like loops and uh spins and rolls and like loops and uh spins and rolls and like loops and uh spins and rolls and really learning how to control the really learning how to control the really learning how to control the airplane at all areas of the envelope. airplane at all areas of the envelope. airplane at all areas of the envelope. You know, really beyond the normal You know, really beyond the normal You know, really beyond the normal straight and level flying. And it's straight and level flying. And it's straight and level flying. And it's super fun because it's like creating super fun because it's like creating super fun because it's like creating your own roller coaster in the sky. your own roller coaster in the sky. your own roller coaster in the sky. >> And it's not scary? >> And it's not scary? >> And it's not scary? >> It's It can be scary sometimes. >> It's It can be scary sometimes. >> It's It can be scary sometimes. >> a daredevil. >> a daredevil. >> a daredevil. >> No, I I enjoy it because it's it's >> No, I I enjoy it because it's it's >> No, I I enjoy it because it's it's challenging, it's interesting, it's a challenging, it's interesting, it's a challenging, it's interesting, it's a different perspective, and it's a way to different perspective, and it's a way to different perspective, and it's a way to learn enough about how the plane behaves learn enough about how the plane behaves learn enough about how the plane behaves to be safer when you're trying to just to be safer when you're trying to just to be safer when you're trying to just fly straight and level. Sometimes things fly straight and level. Sometimes things fly straight and level. Sometimes things happen and you need to learn how to happen and you need to learn how to happen and you need to learn how to recover. So, I do it because it's a recover. So, I do it because it's a recover. So, I do it because it's a challenge, because I enjoy it. I'm not challenge, because I enjoy it. I'm not challenge, because I enjoy it. I'm not an adrenaline junkie in any way. Um but an adrenaline junkie in any way. Um but an adrenaline junkie in any way. Um but uh it's it's just something that I feel uh it's it's just something that I feel uh it's it's just something that I feel like it it can make you a better pilot like it it can make you a better pilot like it it can make you a better pilot and it's just a a different way of and it's just a a different way of and it's just a a different way of seeing the world.

seeing the world. seeing the world. >> Has flying given you a different >> Has flying given you a different >> Has flying given you a different perspective on your work as a perspective on your work as a perspective on your work as a cosmologist? cosmologist? cosmologist? >> I think what it has done is it's allowed >> I think what it has done is it's allowed >> I think what it has done is it's allowed me to have a space where I don't think me to have a space where I don't think me to have a space where I don't think about work, actually. It's um when you about work, actually. It's um when you about work, actually. It's um when you are fully fully in absorbed in something are fully fully in absorbed in something are fully fully in absorbed in something and fully focused, it's you you get into and fully focused, it's you you get into and fully focused, it's you you get into this zone where nothing else can touch this zone where nothing else can touch this zone where nothing else can touch you. And when you're flying, you have to you. And when you're flying, you have to you. And when you're flying, you have to be focused. You can't think about other be focused. You can't think about other be focused. You can't think about other things because things will go very badly things because things will go very badly things because things will go very badly if you if you take your focus away from if you if you take your focus away from if you if you take your focus away from what you're doing. And so, I really what you're doing. And so, I really what you're doing. And so, I really enjoy that that opportunity to enjoy that that opportunity to enjoy that that opportunity to just be in the moment, be in the plane, just be in the moment, be in the plane, just be in the moment, be in the plane, have that different view of the world, have that different view of the world, have that different view of the world, um and and I enjoy, you know, the extra um and and I enjoy, you know, the extra um and and I enjoy, you know, the extra challenge of of trying to do something challenge of of trying to do something challenge of of trying to do something else. else. else. >> Your grandfather worked on the Apollo 11 >> Your grandfather worked on the Apollo 11 >> Your grandfather worked on the Apollo 11 mission. mission. mission. >> Yes. >> Yes. >> Yes. >> And I believed he saved the lives of the >> And I believed he saved the lives of the >> And I believed he saved the lives of the Apollo 11 astronauts. Can you share some Apollo 11 astronauts. Can you share some Apollo 11 astronauts. Can you share some of that story with us? of that story with us? of that story with us? >> Yes. So, my grandfather was a >> Yes. So, my grandfather was a >> Yes. So, my grandfather was a meteorologist in the Navy and um he meteorologist in the Navy and um he meteorologist in the Navy and um he worked on things like um worked on things like um worked on things like um creating uh satellite views of the creating uh satellite views of the creating uh satellite views of the weather with these new rockets that weather with these new rockets that weather with these new rockets that they'd just developed. And he was asked they'd just developed. And he was asked they'd just developed. And he was asked to help with the Apollo 11 mission, and to help with the Apollo 11 mission, and to help with the Apollo 11 mission, and his job was to figure out if the weather his job was to figure out if the weather his job was to figure out if the weather conditions at the splashdown site, when conditions at the splashdown site, when conditions at the splashdown site, when the capsule came back, were going to be the capsule came back, were going to be the capsule came back, were going to be okay, right? Because you you don't want okay, right? Because you you don't want okay, right? Because you you don't want to come into a storm when you're when to come into a storm when you're when to come into a storm when you're when the capsule's coming in on the the capsule's coming in on the the capsule's coming in on the parachutes.

parachutes. parachutes. And he was, you know, checking all the And he was, you know, checking all the And he was, you know, checking all the usual charts, and it looked fine, but he usual charts, and it looked fine, but he usual charts, and it looked fine, but he knew there was a a secret satellite that knew there was a a secret satellite that knew there was a a secret satellite that was a weather satellite, but it was a was a weather satellite, but it was a was a weather satellite, but it was a secret because it could also be used for secret because it could also be used for secret because it could also be used for spying, and he had been in the Navy. Um spying, and he had been in the Navy. Um spying, and he had been in the Navy. Um and he wanted to make sure that there and he wanted to make sure that there and he wanted to make sure that there was nothing in the splashdown area that was nothing in the splashdown area that was nothing in the splashdown area that was going to be a problem. So, he went was going to be a problem. So, he went was going to be a problem. So, he went over to his connections through the Navy over to his connections through the Navy over to his connections through the Navy and checked on that satellite, and it and checked on that satellite, and it and checked on that satellite, and it turned out that the splashdown zone that turned out that the splashdown zone that turned out that the splashdown zone that they'd designated had a a storm coming, they'd designated had a a storm coming, they'd designated had a a storm coming, something called screaming eagle something called screaming eagle something called screaming eagle thunderclouds. Something really bad thunderclouds. Something really bad thunderclouds. Something really bad >> That doesn't sound good. >> That doesn't sound good. >> That doesn't sound good. >> no. And apparently, it was it was bad >> no. And apparently, it was it was bad >> no. And apparently, it was it was bad enough that it could have just ripped enough that it could have just ripped enough that it could have just ripped the parachutes right off the capsule as the parachutes right off the capsule as the parachutes right off the capsule as it was coming in. And so, he managed to it was coming in. And so, he managed to it was coming in. And so, he managed to convince NASA to move the splashdown convince NASA to move the splashdown convince NASA to move the splashdown site just 72 hours before the site just 72 hours before the site just 72 hours before the splashdown, and he couldn't tell them splashdown, and he couldn't tell them splashdown, and he couldn't tell them why because NASA's a civilian agency, why because NASA's a civilian agency, why because NASA's a civilian agency, they couldn't know about these secret they couldn't know about these secret they couldn't know about these secret satellites. And so, he had to just use satellites. And so, he had to just use satellites. And so, he had to just use the weight of his expertise and his the weight of his expertise and his the weight of his expertise and his reputation to tell them, "You have to reputation to tell them, "You have to reputation to tell them, "You have to move the splashdown. I cannot tell you move the splashdown. I cannot tell you move the splashdown. I cannot tell you why. Here's an alternative." And so, why. Here's an alternative." And so, why. Here's an alternative." And so, they moved it a few hundred kilometers they moved it a few hundred kilometers they moved it a few hundred kilometers uh in some direction, and it was fine.

uh in some direction, and it was fine. uh in some direction, and it was fine. But, But, But, >> So, basically, it was a trust me, I've >> So, basically, it was a trust me, I've >> So, basically, it was a trust me, I've got this. got this. got this. >> Yeah, but they did say, "We are also >> Yeah, but they did say, "We are also >> Yeah, but they did say, "We are also going to send some planes to the going to send some planes to the going to send some planes to the original site, and if it's fine there, original site, and if it's fine there, original site, and if it's fine there, you're in trouble." you're in trouble." you're in trouble." They did send the planes. There was They did send the planes. There was They did send the planes. There was There there was a storm, There there was a storm, There there was a storm, um but the astronauts were were fine. um but the astronauts were were fine. um but the astronauts were were fine. >> You said you were a curious child drawn >> You said you were a curious child drawn >> You said you were a curious child drawn to the night sky before you even knew to the night sky before you even knew to the night sky before you even knew the word cosmology. the word cosmology. the word cosmology. Were you influenced by your Were you influenced by your Were you influenced by your grandfather's work? grandfather's work? grandfather's work? >> I was definitely influenced by him as a >> I was definitely influenced by him as a >> I was definitely influenced by him as a scientist. So, I knew him scientist. So, I knew him scientist. So, I knew him I didn't know him through his Apollo 11 I didn't know him through his Apollo 11 I didn't know him through his Apollo 11 work, because that was actually work, because that was actually work, because that was actually classified until I was sort of an classified until I was sort of an classified until I was sort of an adolescent, but I knew him through adolescent, but I knew him through adolescent, but I knew him through just his expertise about the weather. Um just his expertise about the weather. Um just his expertise about the weather. Um I knew him through He was a volunteer at I knew him through He was a volunteer at I knew him through He was a volunteer at the Monterey Bay Aquarium. Uh so, he the Monterey Bay Aquarium. Uh so, he the Monterey Bay Aquarium. Uh so, he knew everything about the sea animals, knew everything about the sea animals, knew everything about the sea animals, and I I just loved to see him talk about and I I just loved to see him talk about and I I just loved to see him talk about the things he was excited about. And And the things he was excited about. And And the things he was excited about. And And he had gone to Caltech as a as a student he had gone to Caltech as a as a student he had gone to Caltech as a as a student to learn about meteorology. And so, I I to learn about meteorology. And so, I I to learn about meteorology. And so, I I I knew a little bit about Caltech and I knew a little bit about Caltech and I knew a little bit about Caltech and about the, you know, all the nerdy about the, you know, all the nerdy about the, you know, all the nerdy people there doing fun, exciting people there doing fun, exciting people there doing fun, exciting science. And so, he was definitely an science. And so, he was definitely an science. And so, he was definitely an influence in getting me excited about influence in getting me excited about influence in getting me excited about science.

science. science. >> Katie, you've written about how you were >> Katie, you've written about how you were >> Katie, you've written about how you were just 10 years old 10 years old when you just 10 years old 10 years old when you just 10 years old 10 years old when you read Stephen Hawking's book A Brief read Stephen Hawking's book A Brief read Stephen Hawking's book A Brief History of Time. History of Time. History of Time. >> Mhm. >> Mhm. >> Mhm. >> I had to read that book really, really >> I had to read that book really, really >> I had to read that book really, really slowly to grasp what he was writing, and slowly to grasp what he was writing, and slowly to grasp what he was writing, and I did that when I was 30. I did that when I was 30. I did that when I was 30. >> Yeah. Yeah. >> Yeah. Yeah. >> Yeah. Yeah. >> how did you first hear about the book >> how did you first hear about the book >> how did you first hear about the book when you were 10 years old? And what when you were 10 years old? And what when you were 10 years old? And what What provoked you to pick it up and What provoked you to pick it up and What provoked you to pick it up and start reading it? start reading it? start reading it? >> I think that I >> I think that I >> I think that I you know, I had exposure to a lot of you know, I had exposure to a lot of you know, I had exposure to a lot of different kinds of science through just different kinds of science through just different kinds of science through just my my family. I think my family picked my my family. I think my family picked my my family. I think my family picked up on the fact that I was curious. I was up on the fact that I was curious. I was up on the fact that I was curious. I was always a tinkerer. I was taking things always a tinkerer. I was taking things always a tinkerer. I was taking things apart and putting them back together, apart and putting them back together, apart and putting them back together, you know, sometimes correctly. And I I you know, sometimes correctly. And I I you know, sometimes correctly. And I I they knew that I was trying to they knew that I was trying to they knew that I was trying to understand everything. And so I had understand everything. And so I had understand everything. And so I had subscriptions to children's magazines subscriptions to children's magazines subscriptions to children's magazines about science and stuff like that. And about science and stuff like that. And about science and stuff like that. And um my my mom is a big science fiction um um my my mom is a big science fiction um um my my mom is a big science fiction um fan. And so I was reading her science fan. And so I was reading her science fan. And so I was reading her science fiction stuff. And every once in a while fiction stuff. And every once in a while fiction stuff. And every once in a while there would be like a public talk about there would be like a public talk about there would be like a public talk about science somewhere in our area. We lived science somewhere in our area. We lived science somewhere in our area. We lived in the LA area. And so she'd take me to in the LA area. And so she'd take me to in the LA area. And so she'd take me to talks by scientists. And so I think I talks by scientists. And so I think I talks by scientists. And so I think I just kind of accumulated um some of just kind of accumulated um some of just kind of accumulated um some of those books. And and uh when I read those books. And and uh when I read those books. And and uh when I read Hawking's book, I didn't understand very Hawking's book, I didn't understand very Hawking's book, I didn't understand very much of it as a 10-year-old, but I knew much of it as a 10-year-old, but I knew much of it as a 10-year-old, but I knew >> you reading it then?

>> you reading it then? >> you reading it then? >> I just wanted to know. I just really I >> I just wanted to know. I just really I >> I just wanted to know. I just really I really wanted to try to understand this really wanted to try to understand this really wanted to try to understand this stuff. And I thought, you know, if I stuff. And I thought, you know, if I stuff. And I thought, you know, if I keep studying, I'll I'll I'll get this. keep studying, I'll I'll I'll get this. keep studying, I'll I'll I'll get this. And I'll I'll maybe be able to work in And I'll I'll maybe be able to work in And I'll I'll maybe be able to work in this area. I didn't know before I read this area. I didn't know before I read this area. I didn't know before I read that book that you could be a that book that you could be a that book that you could be a cosmologist, you know. I saw that cosmologist, you know. I saw that cosmologist, you know. I saw that Stephen Hawking is called a cosmologist. Stephen Hawking is called a cosmologist. Stephen Hawking is called a cosmologist. I was like, you know, what is that? What I was like, you know, what is that? What I was like, you know, what is that? What is that work? And I thought, well, is that work? And I thought, well, is that work? And I thought, well, that's what I want to do. I want to that's what I want to do. I want to that's what I want to do. I want to study the universe. I want to study the study the universe. I want to study the study the universe. I want to study the Big Bang and black holes and and Big Bang and black holes and and Big Bang and black holes and and space-time. I thought that sounded space-time. I thought that sounded space-time. I thought that sounded really cool. really cool. really cool. >> You attended Caltech for your undergrad >> You attended Caltech for your undergrad >> You attended Caltech for your undergrad education and graduated with a degree in education and graduated with a degree in education and graduated with a degree in physics. And you said that theoretical physics. And you said that theoretical physics. And you said that theoretical physics is not just a discipline of a of physics is not just a discipline of a of physics is not just a discipline of a of equations, equations, equations, >> Mhm. >> Mhm. >> Mhm. >> but of imagination. >> but of imagination. >> but of imagination. >> Yeah. Yeah. >> Yeah. Yeah. >> Yeah. Yeah. >> Um how so? >> Um how so? >> Um how so? >> You know, theoretical physics in general >> You know, theoretical physics in general >> You know, theoretical physics in general is the attempt to create kind of a is the attempt to create kind of a is the attempt to create kind of a mathematical cartoon of the world. So, mathematical cartoon of the world. So, mathematical cartoon of the world. So, you know, we have certain observations, you know, we have certain observations, you know, we have certain observations, we get data, and we try to find a a way we get data, and we try to find a a way we get data, and we try to find a a way to connect that data to whatever the to connect that data to whatever the to connect that data to whatever the input was. And and so we build sort of input was. And and so we build sort of input was. And and so we build sort of mathematical machine as a way to figure mathematical machine as a way to figure mathematical machine as a way to figure out how that all fits together. And you out how that all fits together. And you out how that all fits together. And you have to be creative. You have to, you have to be creative. You have to, you have to be creative. You have to, you know, think about like, what are the know, think about like, what are the know, think about like, what are the possibilities here? What are the things, possibilities here? What are the things, possibilities here? What are the things, you know, what kinds of symmetries can I you know, what kinds of symmetries can I you know, what kinds of symmetries can I find in this system, you know, how do find in this system, you know, how do find in this system, you know, how do how are the these things similar to how are the these things similar to how are the these things similar to these other things? So, it's very these other things? So, it's very these other things? So, it's very creative, it's very interactive, you creative, it's very interactive, you creative, it's very interactive, you know, there's the theoretical physics know, there's the theoretical physics know, there's the theoretical physics community is extremely collaborative, community is extremely collaborative, community is extremely collaborative, you know, everybody's gathered around you know, everybody's gathered around you know, everybody's gathered around chalkboards arguing about equations and, chalkboards arguing about equations and, chalkboards arguing about equations and, you know, going to conferences all the you know, going to conferences all the you know, going to conferences all the time giving talks, you know, we don't we

time giving talks, you know, we don't we time giving talks, you know, we don't we don't sit in isolation, you know, just don't sit in isolation, you know, just don't sit in isolation, you know, just writing down equations by ourselves. writing down equations by ourselves. writing down equations by ourselves. It's it's always a conversation and it's It's it's always a conversation and it's It's it's always a conversation and it's always it's it's it's very much a always it's it's it's very much a always it's it's it's very much a creative, imaginative kind of work. creative, imaginative kind of work. creative, imaginative kind of work. >> You went on to Princeton University for >> You went on to Princeton University for >> You went on to Princeton University for your PhD, where your doctoral research your PhD, where your doctoral research your PhD, where your doctoral research focused on early universe cosmology, focused on early universe cosmology, focused on early universe cosmology, cosmic inflation, and dark matter. And cosmic inflation, and dark matter. And cosmic inflation, and dark matter. And you've written about how much of you've written about how much of you've written about how much of cosmology is trying to tell a story from cosmology is trying to tell a story from cosmology is trying to tell a story from the faintest traces of light. the faintest traces of light. the faintest traces of light. >> Mhm. >> Mhm. >> Mhm. >> Katie, how are you able to decipher >> Katie, how are you able to decipher >> Katie, how are you able to decipher those earliest traces? And what are some those earliest traces? And what are some those earliest traces? And what are some of the most important things you've of the most important things you've of the most important things you've learned about that light? learned about that light? learned about that light? >> Yeah, so, um, I think in that in that I >> Yeah, so, um, I think in that in that I >> Yeah, so, um, I think in that in that I must have been talking about the cosmic must have been talking about the cosmic must have been talking about the cosmic microwave background, which is light microwave background, which is light microwave background, which is light that's all around us in the universe. that's all around us in the universe. that's all around us in the universe. Um, if you if you tune a a microwave Um, if you if you tune a a microwave Um, if you if you tune a a microwave receiver, so, microwaves are just a kind receiver, so, microwaves are just a kind receiver, so, microwaves are just a kind of light, a kind of electromagnetic of light, a kind of electromagnetic of light, a kind of electromagnetic radiation. Um, and if you tune your radiation. Um, and if you tune your radiation. Um, and if you tune your receiver to the right frequencies, you receiver to the right frequencies, you receiver to the right frequencies, you can see this background of just a glow can see this background of just a glow can see this background of just a glow all around you everywhere in space. And, all around you everywhere in space. And, all around you everywhere in space. And, um, that's the light from the Big Bang.

um, that's the light from the Big Bang. um, that's the light from the Big Bang. And and the way that we know that what And and the way that we know that what And and the way that we know that what that is is that we can look at the that is is that we can look at the that is is that we can look at the spectrum of that light, how much energy spectrum of that light, how much energy spectrum of that light, how much energy is at different frequencies, and we can is at different frequencies, and we can is at different frequencies, and we can see that the spectrum is exactly the see that the spectrum is exactly the see that the spectrum is exactly the same spectrum you get when something is same spectrum you get when something is same spectrum you get when something is glowing because it's hot. Like, if you glowing because it's hot. Like, if you glowing because it's hot. Like, if you take a poker and you stick it in the take a poker and you stick it in the take a poker and you stick it in the fire, it glows red, and that has a fire, it glows red, and that has a fire, it glows red, and that has a certain spectrum, a certain distribution certain spectrum, a certain distribution certain spectrum, a certain distribution of light. And it's just anything you of light. And it's just anything you of light. And it's just anything you heat up that glows, it glows because heat up that glows, it glows because heat up that glows, it glows because it's hot, it's because of the way the it's hot, it's because of the way the it's hot, it's because of the way the particles are moving around and creating particles are moving around and creating particles are moving around and creating light. And this background light has light. And this background light has light. And this background light has exactly the same spectrum and is exactly the same spectrum and is exactly the same spectrum and is everywhere in space. And so what it is everywhere in space. And so what it is everywhere in space. And so what it is is is if you look far enough away in any is is if you look far enough away in any is is if you look far enough away in any direction, you're looking so far away direction, you're looking so far away direction, you're looking so far away that the light has taken a really long that the light has taken a really long that the light has taken a really long time to get to you. Um you know, light time to get to you. Um you know, light time to get to you. Um you know, light takes some time to travel. So, you know, takes some time to travel. So, you know, takes some time to travel. So, you know, even in this room, you know, you're even in this room, you know, you're even in this room, you know, you're maybe 6 ft away from me. It takes about maybe 6 ft away from me. It takes about maybe 6 ft away from me. It takes about 6 nanoseconds for the light to get from 6 nanoseconds for the light to get from 6 nanoseconds for the light to get from you to me. So, you're you're 6 you to me. So, you're you're 6 you to me. So, you're you're 6 nanoseconds in the past to me. nanoseconds in the past to me. nanoseconds in the past to me. >> And you are to me. >> And you are to me. >> And you are to me. >> And you and I am to you. But if I look >> And you and I am to you. But if I look >> And you and I am to you. But if I look far enough out in the cosmos, I can look far enough out in the cosmos, I can look far enough out in the cosmos, I can look billions of years in the past and I'm billions of years in the past and I'm billions of years in the past and I'm seeing directly that the past. And if seeing directly that the past. And if seeing directly that the past. And if you look so far away that you're looking you look so far away that you're looking you look so far away that you're looking 13.8 billion years ago, you're looking 13.8 billion years ago, you're looking 13.8 billion years ago, you're looking at the time when the whole universe was at the time when the whole universe was at the time when the whole universe was glowing with heat because it was in this glowing with heat because it was in this glowing with heat because it was in this this hot dense phase of the very early this hot dense phase of the very early this hot dense phase of the very early universe. And so you see that glow very universe. And so you see that glow very universe. And so you see that glow very directly in the cosmic microwave directly in the cosmic microwave directly in the cosmic microwave background. And that's that's something background. And that's that's something background. And that's that's something that we can study. We can study that that we can study. We can study that that we can study. We can study that glow because we are looking directly at glow because we are looking directly at glow because we are looking directly at the very very early universe. It's the very very early universe. It's the very very early universe. It's incredible.

incredible. incredible. >> Given that light travels, the light that >> Given that light travels, the light that >> Given that light travels, the light that is being picked up in this background, is being picked up in this background, is being picked up in this background, where is that going? where is that going? where is that going? >> It's it's just it's just diffusing >> It's it's just it's just diffusing >> It's it's just it's just diffusing through space. So, it's going in every through space. So, it's going in every through space. So, it's going in every direction. direction. direction. >> So, it's just continually moving. >> So, it's just continually moving. >> So, it's just continually moving. >> Yeah. Yeah. So, if you turn on a light >> Yeah. Yeah. So, if you turn on a light >> Yeah. Yeah. So, if you turn on a light bulb, the light moves out in every bulb, the light moves out in every bulb, the light moves out in every direction and you know, the light from direction and you know, the light from direction and you know, the light from the the the time the whole universe was the the the time the whole universe was the the the time the whole universe was glowing with heat, you know, that light glowing with heat, you know, that light glowing with heat, you know, that light was just moving in every direction. was just moving in every direction. was just moving in every direction. Eventually, the universe cooled down and Eventually, the universe cooled down and Eventually, the universe cooled down and light, you know, kept traveling in every light, you know, kept traveling in every light, you know, kept traveling in every direction and the places we see it at direction and the places we see it at direction and the places we see it at the sort of edges of our vision in the the sort of edges of our vision in the the sort of edges of our vision in the universe, that light is also going away universe, that light is also going away universe, that light is also going away from us. But the part that's going from us. But the part that's going from us. But the part that's going toward us, we see and we see that that toward us, we see and we see that that toward us, we see and we see that that background radiation. background radiation. background radiation. >> Voyager is not even one full light day >> Voyager is not even one full light day >> Voyager is not even one full light day away from Earth. away from Earth. away from Earth. But it's going to be another 40,000 But it's going to be another 40,000 But it's going to be another 40,000 years before it encounters another years before it encounters another years before it encounters another celestial body. celestial body. celestial body. >> Yeah. >> Yeah. >> Yeah. >> Cosmology often deals with scales that >> Cosmology often deals with scales that >> Cosmology often deals with scales that defy comprehension. How do you hold on defy comprehension. How do you hold on defy comprehension. How do you hold on to the human scale with this sort of to the human scale with this sort of to the human scale with this sort of infinite, what seems like it's infinite?

infinite, what seems like it's infinite? infinite, what seems like it's infinite? >> I mean, I can't conceptualize these >> I mean, I can't conceptualize these >> I mean, I can't conceptualize these scales really any more than anyone else scales really any more than anyone else scales really any more than anyone else can, you know, what we we talk about, can, you know, what we we talk about, can, you know, what we we talk about, you know, billions of light years and you know, billions of light years and you know, billions of light years and and all this stuff and and I I just have and all this stuff and and I I just have and all this stuff and and I I just have to write down the number and trust it. I to write down the number and trust it. I to write down the number and trust it. I don't I don't have a sense, you know, I don't I don't have a sense, you know, I don't I don't have a sense, you know, I can't hold in my head this this notion can't hold in my head this this notion can't hold in my head this this notion of, you know, that much space or that of, you know, that much space or that of, you know, that much space or that much time. Um so for me, you know, much time. Um so for me, you know, much time. Um so for me, you know, there's there's a kind of there's there's a kind of there's there's a kind of you know, sort of a a ruler in my mind you know, sort of a a ruler in my mind you know, sort of a a ruler in my mind of, you know, million, billion, trillion of, you know, million, billion, trillion of, you know, million, billion, trillion and I don't have a sense for how far and I don't have a sense for how far and I don't have a sense for how far apart those are. I just know that these apart those are. I just know that these apart those are. I just know that these are the scales that I'm working with and are the scales that I'm working with and are the scales that I'm working with and then I I think about on the human scale, then I I think about on the human scale, then I I think about on the human scale, you know, what what I can do as a as a you know, what what I can do as a as a you know, what what I can do as a as a scientist to try to understand it, but scientist to try to understand it, but scientist to try to understand it, but um you know, my work on my in my work um you know, my work on my in my work um you know, my work on my in my work even even individual galaxies are are even even individual galaxies are are even even individual galaxies are are not that important. not that important. not that important. >> [laughter] >> [laughter] >> [laughter] >> Let alone us. >> Let alone us. >> Let alone us. >> Yeah, I mean, professionally I I you >> Yeah, I mean, professionally I I you >> Yeah, I mean, professionally I I you know, all the human stuff is kind of know, all the human stuff is kind of know, all the human stuff is kind of lost in the weeds. Um but but the the lost in the weeds. Um but but the the lost in the weeds. Um but but the the work itself is is very human because work itself is is very human because work itself is is very human because we're all working together and we're all we're all working together and we're all we're all working together and we're all having this continual conversation and having this continual conversation and having this continual conversation and the mathematical models we're building the mathematical models we're building the mathematical models we're building are very much tied to our humanity are very much tied to our humanity are very much tied to our humanity because these are, you know, just things because these are, you know, just things because these are, you know, just things that come out of our our imaginations that come out of our our imaginations that come out of our our imaginations that are tested with the data and we are that are tested with the data and we are that are tested with the data and we are constantly making choices and constantly making choices and constantly making choices and constantly, you know, trying to better constantly, you know, trying to better constantly, you know, trying to better understand the universe we live in.

understand the universe we live in. understand the universe we live in. >> What provoked you to choose a field that >> What provoked you to choose a field that >> What provoked you to choose a field that is primarily about how we end? is primarily about how we end? is primarily about how we end? >> [laughter] >> [laughter] >> [laughter] >> Um so >> Um so >> Um so I'm really interested in the whole story I'm really interested in the whole story I'm really interested in the whole story of the universe. So I've done a lot of of the universe. So I've done a lot of of the universe. So I've done a lot of work about the beginning of the universe work about the beginning of the universe work about the beginning of the universe and I've worked on how the universe and I've worked on how the universe and I've worked on how the universe evolves over time, how the first stars evolves over time, how the first stars evolves over time, how the first stars formed, how the dark matter, this formed, how the dark matter, this formed, how the dark matter, this invisible stuff that holds galaxies invisible stuff that holds galaxies invisible stuff that holds galaxies together, how that's evolved over time together, how that's evolved over time together, how that's evolved over time and brought galaxies into existence. And and brought galaxies into existence. And and brought galaxies into existence. And at some point I started getting really at some point I started getting really at some point I started getting really curious about the end as well and curious about the end as well and curious about the end as well and I just, you know, we know the universe I just, you know, we know the universe I just, you know, we know the universe is evolving and changing and we know is evolving and changing and we know is evolving and changing and we know that it's not going to be the same that it's not going to be the same that it's not going to be the same forever. It's going to be different and forever. It's going to be different and forever. It's going to be different and it's it's it's it's it's it's we we know that there was it was we we know that there was it was we we know that there was it was different in the beginning and it's different in the beginning and it's different in the beginning and it's changing and it's going to be real changing and it's going to be real changing and it's going to be real different in the future. And so, I'm different in the future. And so, I'm different in the future. And so, I'm really curious what that ending looks really curious what that ending looks really curious what that ending looks like and so that's why I wrote a book like and so that's why I wrote a book like and so that's why I wrote a book about the end of the universe just cuz about the end of the universe just cuz about the end of the universe just cuz I'm I wanted to talk about, you know, I'm I wanted to talk about, you know, I'm I wanted to talk about, you know, what are the possibilities? What are we what are the possibilities? What are we what are the possibilities? What are we thinking about how the universe will end thinking about how the universe will end thinking about how the universe will end and like what is that whole story, you and like what is that whole story, you and like what is that whole story, you know? I When you read a story, you want know? I When you read a story, you want know? I When you read a story, you want to know the beginning, the middle, and to know the beginning, the middle, and to know the beginning, the middle, and the end and and you know, I feel like the end and and you know, I feel like the end and and you know, I feel like it's it's really part of how we fit into it's it's really part of how we fit into it's it's really part of how we fit into this cosmos.

this cosmos. this cosmos. >> Your book is titled The End of >> Your book is titled The End of >> Your book is titled The End of Everything and in it you explore five Everything and in it you explore five Everything and in it you explore five possible endings for the cosmos. The Big possible endings for the cosmos. The Big possible endings for the cosmos. The Big Crunch, Heat Death, The Big Rip, Vacuum Crunch, Heat Death, The Big Rip, Vacuum Crunch, Heat Death, The Big Rip, Vacuum Decay, and Bounce. Were there others Decay, and Bounce. Were there others Decay, and Bounce. Were there others that you left out or is this the only that you left out or is this the only that you left out or is this the only five options? five options? five options? >> Um [laughter] >> Um [laughter] >> Um [laughter] So, I focus on sort of five categories So, I focus on sort of five categories So, I focus on sort of five categories of endings that are things that are of endings that are things that are of endings that are things that are actually talked about in the physics actually talked about in the physics actually talked about in the physics literature. So, all of these are literature. So, all of these are literature. So, all of these are possibilities that physicists have put possibilities that physicists have put possibilities that physicists have put together models, we've together models, we've together models, we've you know, worked out what what the you know, worked out what what the you know, worked out what what the physics would be in each of these physics would be in each of these physics would be in each of these scenarios. scenarios. scenarios. There are there are ways to to tweak There are there are ways to to tweak There are there are ways to to tweak each of these where they're going to be each of these where they're going to be each of these where they're going to be a little bit different, but basically, a little bit different, but basically, a little bit different, but basically, you know, in terms of the whole cosmos, you know, in terms of the whole cosmos, you know, in terms of the whole cosmos, there there are only a finite number of there there are only a finite number of there there are only a finite number of ways that it can be destroyed, ways that it can be destroyed, ways that it can be destroyed, >> [laughter] >> [laughter] >> [laughter] >> like it can it can collapse, it can keep >> like it can it can collapse, it can keep >> like it can it can collapse, it can keep going, going, going, you can have these weird transitions you can have these weird transitions you can have these weird transitions where there's basically a bubble of where there's basically a bubble of where there's basically a bubble of of a new kind of space that spreads of a new kind of space that spreads of a new kind of space that spreads through the universe and destroys through the universe and destroys through the universe and destroys everything. And then there's like cyclic everything. And then there's like cyclic everything. And then there's like cyclic models and that's models and that's models and that's and there are a lot of different ways and there are a lot of different ways and there are a lot of different ways where the universe can end and start where the universe can end and start where the universe can end and start again or or the beginning of our again or or the beginning of our again or or the beginning of our universe could be the end of a previous universe could be the end of a previous universe could be the end of a previous universe and there are are a few of universe and there are are a few of universe and there are are a few of those that I talk about in the book as those that I talk about in the book as those that I talk about in the book as well.

well. well. >> that that to me feels the most hopeful. >> that that to me feels the most hopeful. >> that that to me feels the most hopeful. Um Um Um >> [laughter] >> [laughter] >> [laughter] >> You've said that writing this book >> You've said that writing this book >> You've said that writing this book changed your relationship to time. changed your relationship to time. changed your relationship to time. >> Yeah. >> Yeah. >> Yeah. >> In what way? >> In what way? >> In what way? >> You know, talking about the very very >> You know, talking about the very very >> You know, talking about the very very distant future of the universe, you you distant future of the universe, you you distant future of the universe, you you really think about this kind of deep really think about this kind of deep really think about this kind of deep time idea and and how time idea and and how time idea and and how you know, the the bit of time we live in you know, the the bit of time we live in you know, the the bit of time we live in is so small. Um and the the bit of time is so small. Um and the the bit of time is so small. Um and the the bit of time humanity has existed in is so small and humanity has existed in is so small and humanity has existed in is so small and and there's there was time before us and and there's there was time before us and and there's there was time before us and there's going to be so much time after there's going to be so much time after there's going to be so much time after us. us. us. Um and it made me think a lot about not Um and it made me think a lot about not Um and it made me think a lot about not just time but like just time but like just time but like how our impact on the world, you know, how our impact on the world, you know, how our impact on the world, you know, we we are really unimportant in the we we are really unimportant in the we we are really unimportant in the universe. Just to say [laughter] like universe. Just to say [laughter] like universe. Just to say [laughter] like like uh humanity is is completely like uh humanity is is completely like uh humanity is is completely insignificant in the cosmos in every insignificant in the cosmos in every insignificant in the cosmos in every possible way you can imagine. Um possible way you can imagine. Um possible way you can imagine. Um but uh but uh but uh >> Optimistic morning, folks. >> Optimistic morning, folks. >> Optimistic morning, folks. >> I mean, but you know, I mean, >> I mean, but you know, I mean, >> I mean, but you know, I mean, we are it's impressive that we know so we are it's impressive that we know so we are it's impressive that we know so much but even though we are so much but even though we are so much but even though we are so insignificant. Um insignificant. Um insignificant. Um but uh you know, it made me think about but uh you know, it made me think about but uh you know, it made me think about like like like you know, everything is is going to end you know, everything is is going to end you know, everything is is going to end at some point and there's not going to at some point and there's not going to at some point and there's not going to be some you know, final thing that makes be some you know, final thing that makes be some you know, final thing that makes it all worthwhile, right? At some point it all worthwhile, right? At some point it all worthwhile, right? At some point everything will be destroyed. It kind of everything will be destroyed. It kind of everything will be destroyed. It kind of won't have mattered that we were here.

won't have mattered that we were here. won't have mattered that we were here. Um so when we have think about how to Um so when we have think about how to Um so when we have think about how to find meaning and purpose, it's find meaning and purpose, it's find meaning and purpose, it's you know, it has to be something that's you know, it has to be something that's you know, it has to be something that's self-contained, you know, something that self-contained, you know, something that self-contained, you know, something that exists in the universe now. And what is exists in the universe now. And what is exists in the universe now. And what is you know, how do we find meaning in the you know, how do we find meaning in the you know, how do we find meaning in the moment? How do we find meaning that moment? How do we find meaning that moment? How do we find meaning that doesn't depend on it all being wrapped doesn't depend on it all being wrapped doesn't depend on it all being wrapped up with a tidy bow, you know, at some up with a tidy bow, you know, at some up with a tidy bow, you know, at some future point. Um and that that really future point. Um and that that really future point. Um and that that really made me think differently about what's made me think differently about what's made me think differently about what's important in my life, um what to be important in my life, um what to be important in my life, um what to be upset about or not upset about, um upset about or not upset about, um upset about or not upset about, um because, you know, we are we are just because, you know, we are we are just because, you know, we are we are just temporary and we are doing the best we temporary and we are doing the best we temporary and we are doing the best we can while we're here. can while we're here. can while we're here. >> Katie, in addition to your work in >> Katie, in addition to your work in >> Katie, in addition to your work in theoretical astrophysics, cosmology, theoretical astrophysics, cosmology, theoretical astrophysics, cosmology, writing, and aerial acrobatics, um writing, and aerial acrobatics, um writing, and aerial acrobatics, um you're also a poet. you're also a poet. you're also a poet. >> [laughter] >> [laughter] >> [laughter] >> I've I've done a little bit of poetry, >> I've I've done a little bit of poetry, >> I've I've done a little bit of poetry, yeah. I I enjoy that. yeah. I I enjoy that. yeah. I I enjoy that. >> I I'm wondering if it's possible I know >> I I'm wondering if it's possible I know >> I I'm wondering if it's possible I know I know we talked a little bit about this I know we talked a little bit about this I know we talked a little bit about this ahead of time, but my TED friends and I ahead of time, but my TED friends and I ahead of time, but my TED friends and I asked if you would read one of your asked if you would read one of your asked if you would read one of your poems today on the TED next stage and poems today on the TED next stage and poems today on the TED next stage and you agreed.

you agreed. you agreed. >> Yeah. >> Yeah. >> Yeah. >> Um >> Um >> Um how lucky are we? how lucky are we? how lucky are we? Um so, can you tell us a little bit Um so, can you tell us a little bit Um so, can you tell us a little bit about what you're going to share with us about what you're going to share with us about what you're going to share with us today? today? today? >> So, I've written a few things here and >> So, I've written a few things here and >> So, I've written a few things here and there. I've done a lot of science there. I've done a lot of science there. I've done a lot of science writing. I've written a few poems. Um writing. I've written a few poems. Um writing. I've written a few poems. Um and at some point I was contacted by a and at some point I was contacted by a and at some point I was contacted by a sort of graphic uh design company saying sort of graphic uh design company saying sort of graphic uh design company saying that they were putting together a sort that they were putting together a sort that they were putting together a sort of reel of their um of reel of their um of reel of their um their work and they wanted uh they their work and they wanted uh they their work and they wanted uh they wanted a poem they wanted to create a wanted a poem they wanted to create a wanted a poem they wanted to create a you know, have a poem to go along with you know, have a poem to go along with you know, have a poem to go along with it and could I write a poem about it and could I write a poem about it and could I write a poem about something science-y and then they would something science-y and then they would something science-y and then they would illustrate it. They they were called illustrate it. They they were called illustrate it. They they were called Finger Industries, now they're called Finger Industries, now they're called Finger Industries, now they're called Ouch Ouch Health. Um and uh and so I Ouch Ouch Health. Um and uh and so I Ouch Ouch Health. Um and uh and so I wrote this poem for for their wrote this poem for for their wrote this poem for for their the their sort of demo reel. the their sort of demo reel. the their sort of demo reel. >> Cool. Wonderful. Would it be okay for >> Cool. Wonderful. Would it be okay for >> Cool. Wonderful. Would it be okay for you to stand? you to stand? you to stand? >> Sure, sure. >> Sure, sure. >> Sure, sure. >> Excellent. Thank you. >> Excellent. Thank you. >> Excellent. Thank you. >> Okay. >> Okay. >> Okay. So, the poem is called Constructs. So, the poem is called Constructs. So, the poem is called Constructs. What do you see when you look at the What do you see when you look at the What do you see when you look at the world? world? world? At this infinite variety of objects, At this infinite variety of objects, At this infinite variety of objects, colors, textures, weights, flavors. colors, textures, weights, flavors. colors, textures, weights, flavors. What makes each person, animal, object What makes each person, animal, object What makes each person, animal, object unique, unique, unique, special?

special? special? There are around 90 chemical elements There are around 90 chemical elements There are around 90 chemical elements naturally found on this planet. naturally found on this planet. naturally found on this planet. But each one But each one But each one hydrogen, oxygen, or carbon hydrogen, oxygen, or carbon hydrogen, oxygen, or carbon is just a construct. is just a construct. is just a construct. A tiny, shivering mass of the same A tiny, shivering mass of the same A tiny, shivering mass of the same protons, neutrons, and electrons protons, neutrons, and electrons protons, neutrons, and electrons found in any other. found in any other. found in any other. Same ingredients, Same ingredients, Same ingredients, different recipe. different recipe. different recipe. We are not essentially our constituent We are not essentially our constituent We are not essentially our constituent parts. parts. parts. We are the knowledge that unites them. We are the knowledge that unites them. We are the knowledge that unites them. >> Katie Mack. >> Katie Mack. >> Katie Mack. >> [applause] >> [applause] >> [applause] >> Thank you so much.